Preparation of an amino-modified biochar supported sulfide nanoscale zero-valent iron composite and its efficient removal of U(vi) from wastewater by adsorption and reduction†
Abstract
Nanoscale zero-valent iron (nZVI) was cured by vulcanization and biochar functionalization to overcome the tendency of oxidation and aggregation, and the sulfurized nano-zero-valent iron functional material supported by amino biochar (SnZVI–BC–NH2) was obtained, which was used to remove U(VI) from wastewater in this study. A variety of measurements (SEM, TEM, XRD, BET, VSM, FT-IR, and XPS) were used to characterize the morphology, structure, magnetic properties, characteristic functional groups and chemical bonds of SnZVI–BC–NH2. Analysis results confirm that the aminated biochar can support sulfurized nZVI well. The good kinetics, thermodynamics, and large removal capacity data (at pH 6, T = 298 K, Qm = 158.1 mg g−1) indicate that SnZVI–BC–NH2 has excellent removal performance for U(VI), and the experimental data are in good agreement with the pseudo-second-order kinetic model. Cycling and anti-oxidation tests demonstrate that the FeSx shell plays a crucial role in enhancing the removal of SnZVI–BC–NH2 on U(VI). XPS and FT-IR analysis results show that SnZVI–BC–NH2 removes U(VI) through the synergistic effect of adsorption and reduction.